Regarding the missing neutral wire in switches. In Denmark we have “solved” this pretty easy, as there is a un-written rule (code), to place an outlet together with a switch, just next to the door when entering a room (or strategic placed).
Here is an example of how it looks from the outside.
On the left: (just right next to the door)
The grey device to the left is the old (more than 40 years old) way of doing it. It consists of a single switch and an outlet. The outlet (bottom of the grey device) is actually a switch/outlet in combination. It was required in the old days to be able to turn on/off the outlet. Its no longer required.
On the right:
The white device is the newer Fuga combination by LK (Laurits Knudsen), which is in used in most places in Denmark.
The combination consist of, (from top to bottom): One single switch, one dual switch and one outlet (notice the outlet without the switch to turn it on/off).
Having this sort of combination there will always be a neutral wire available.
Many many years ago we also had metal pipes. I´m not sure if it´s still legal to use, but I´m pretty sure its no longer available. And havnt been for at least 30 years. Whats even worse, we also had cotton/fabric isolated wires. A very bad combination when watering entering the pipes.
In at least the last 40 years, buildings have been build using PVC pipes and PVC isolated wires.
There are still buildings here, which consist of metal pibes and cotton isolated wires
The worse problem in Denmark is, that the above solution may look good (better) and is pretty smart, as the wall boxes behind is build as gauge/combi sizes from what the user need.
But the problem is, the wall boxes behind is nowhere near any sorts of standard size. Its very small like 50x50mm for a single switch (the width is always the same).
This means, whenever a building is build using Fuga wall boxes, it´s forced to Fuga modules (switches, outlets, dimmers etc) as well, and nothing else.
An example, I cant exhange a switch with a EU size switch. At least not unless I rip out the wall box, and exchange it with an EU size wall box. Atm I´m facing this situation personally, cause I´m testing some Velbus equipment (panels). I cant fit the panels unless I exchange the wall box. Thats not a small peace of rebuilding done in a weekend.
Fortunatly many newer buildings are builded using EU-sized material in the last coupple of years… Beside beeing cheaper it opens up a more flexible market, specially regarding smarthome switches etc.